# Lake County, South Dakota

Lake County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 11,059. Its county seat is Madison. The county was formed in 1873.

## Geography

The terrain of Lake County consists of rolling hills, with the area devoted to agriculture. A tributary of the East Fork Vermillion River flows south-southeastward through the lower western part of the county, and Buffalo Creek flows southeastward from the central part of the county, leaving the county near its southeast corner. The terrain generally slopes to the south, although high points (ca. 1,814' ASL) are found on the north and south boundary lines and points between.
Lake County has a total area of 575 square miles (1,490 km$^2$), of which 563 square miles (1,460 km$^2$) is land and 12 square miles (31 km$^2$) (2.1%) is water.

### Lakes

Source:
* Buffalo Slough
* Brant Lake
* Davis Slough
* Gilman Lake
* Green Lake
* Lake Badus
* Lake Herman
* Lake Madison
* Long Lake
* Mud Lake
* Pelican Lake
* Round Lake
* Spring Lake

### Protected areas

Source:
* Lake Herman State Park
* Walker's Point State Recreation Area

### Major highways

* U.S. Highway 81
* South Dakota Highway 19
* South Dakota Highway 34

### Adjacent counties

* Brookings County - northeast
* Moody County - east
* Minnehaha County - southeast
* McCook County - southwest
* Miner County - west
* Kingsbury County - northwest

## Demographics
### 2020 census

As of the 2020 census, there were 11,059 people, 4,576 households, and 2,804 families residing in the county. The population density was 19.6 inhabitants per square mile (7.6/km$^2$). There were 5,658 housing units.

### 2010 census

As of the 2010 census, there were 11,200 people, 4,483 households, and 2,814 families in the county. The population density was 19.9 inhabitants per square mile (7.7/km$^2$). There were 5,559 housing units at an average density of 9.9 units per square mile (3.8 units/km$^2$). The racial makeup of the county was 96.2% white, 0.7% Asian, 0.7% American Indian, 0.5% black or African American, 0.8% from other races, and 1.1% from two or more races. Those of Hispanic or Latino origin made up 1.6% of the population. In terms of ancestry, 50.7% were German, 20.6% were Norwegian, 12.4% were Irish, 6.6% were English, 6.2% were Dutch, 5.0% were Danish, and 5.0% were American.
Of the 4,483 households, 26.7% had children under the age of 18 living with them, 53.0% were married couples living together, 6.8% had a female householder with no husband present, 37.2% were non-families, and 30.9% of all households were made up of individuals. The average household size was 2.30 and the average family size was 2.88. The median age was 39.9 years.
The median income for a household in the county was $45,606 and the median income for a family was $57,753. Males had a median income of $36,370 versus $25,898 for females. The per capita income for the county was $22,447. About 6.5% of families and 12.1% of the population were below the poverty line, including 12.8% of those under age 18 and 8.8% of those age 65 or over.

## Communities
### City

* Madison (county seat)

### Towns

* Brant Lake
* Nunda
* Ramona

### Village

* Wentworth

### Census-designated places

* Brant Lake South
* Chester
* Graceville Colony
* Lake Madison
* Rustic Acres Colony
* Winfred

### Other unincorporated communities

* Franklin
* Junius
* Rutland

### Townships

* Badus
* Chester
* Clarno
* Concord
* Farmington
* Franklin
* Herman
* Lake View
* Le Roy
* Nunda
* Orland
* Rutland
* Summit
* Wayne
* Wentworth
* Winfred

### Historical townsite

* Saranac

## Politics

Lake County voters have voted for Republican Party candidates in 62 percent of national elections since 1964.
United States presidential election results for Lake County, South Dakota :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 3,819 | 64.66% | 1,978 | 33.49% | 109 | 1.85% |
| 2020 | 3,681 | 62.68% | 2,068 | 35.21% | 124 | 2.11% |
| 2016 | 4,038 | 59.50% | 2,314 | 34.10% | 434 | 6.40% |
| 2012 | 3,419 | 54.40% | 2,724 | 43.34% | 142 | 2.26% |
| 2008 | 2,993 | 48.61% | 3,033 | 49.26% | 131 | 2.13% |
| 2004 | 3,359 | 55.92% | 2,509 | 41.77% | 139 | 2.31% |
| 2000 | 2,724 | 52.85% | 2,331 | 45.23% | 99 | 1.92% |
| 1996 | 1,966 | 38.41% | 2,526 | 49.36% | 626 | 12.23% |
| 1992 | 1,890 | 33.81% | 2,388 | 42.72% | 1,312 | 23.47% |
| 1988 | 2,439 | 47.62% | 2,663 | 51.99% | 20 | 0.39% |
| 1984 | 3,027 | 55.92% | 2,367 | 43.73% | 19 | 0.35% |
| 1980 | 3,093 | 52.85% | 2,207 | 37.71% | 552 | 9.43% |
| 1976 | 2,530 | 46.20% | 2,930 | 53.51% | 16 | 0.29% |
| 1972 | 2,919 | 50.14% | 2,886 | 49.57% | 17 | 0.29% |
| 1968 | 2,876 | 53.68% | 2,294 | 42.81% | 188 | 3.51% |
| 1964 | 2,417 | 44.72% | 2,988 | 55.28% | 0 | 0.00% |
| 1960 | 3,520 | 61.28% | 2,224 | 38.72% | 0 | 0.00% |
| 1956 | 3,404 | 62.32% | 2,058 | 37.68% | 0 | 0.00% |
| 1952 | 4,020 | 73.28% | 1,466 | 26.72% | 0 | 0.00% |
| 1948 | 2,837 | 56.95% | 2,093 | 42.01% | 52 | 1.04% |
| 1944 | 2,956 | 65.70% | 1,543 | 34.30% | 0 | 0.00% |
| 1940 | 4,179 | 68.87% | 1,889 | 31.13% | 0 | 0.00% |
| 1936 | 3,182 | 52.95% | 2,520 | 41.94% | 307 | 5.11% |
| 1932 | 2,222 | 41.09% | 3,090 | 57.15% | 95 | 1.76% |
| 1928 | 3,048 | 63.41% | 1,744 | 36.28% | 15 | 0.31% |
| 1924 | 1,888 | 45.35% | 297 | 7.13% | 1,978 | 47.51% |
| 1920 | 2,333 | 69.98% | 398 | 11.94% | 603 | 18.09% |
| 1916 | 1,398 | 55.04% | 1,027 | 40.43% | 115 | 4.53% |
| 1912 | 0 | 0.00% | 657 | 33.50% | 1,304 | 66.50% |
| 1908 | 1,415 | 65.60% | 636 | 29.49% | 106 | 4.91% |
| 1904 | 1,728 | 78.90% | 260 | 11.87% | 202 | 9.22% |
| 1900 | 1,172 | 55.57% | 901 | 42.72% | 36 | 1.71% |
| 1896 | 864 | 46.10% | 999 | 53.31% | 11 | 0.59% |
| 1892 | 742 | 43.47% | 196 | 11.48% | 769 | 45.05% |